If Africa can cut out banks, why can't we?

Why isn't there a Pirate Bay for banks, where people can send money to each other without having to wait days for it to arrive? One of the continuing mysteries of the web revolution is why the equivalent of an eBay or Amazon hasn't emerged in the banking sector, where vast profits accrue - or used to accrue - to the middlemen. It is a rite of passage for younger people to swap music files, but never money, despite some interesting experiments, such as zopa.com, where borrowers can get money from lenders without banks being involved.

If you want to see pioneering experiments in banking you will have to go to a surprising place - Africa. And the question is, why can't we do the same here? If the Post Office is looking for a new role, it need look no farther. In Kenya, customers of M-Pesa can send money to each other from around the country in 14 seconds flat using their mobiles. In the UK it takes three days, thereby endowing the banks with a huge float of money in transit on which they can earn interest. In Kenya, people leave their money at a trusted outlet such as a shop or pharmacy, where it is loaded into their sim cards.

At a Forum Oxford future technologies conference at the weekend we were updated on the startling success of the operation. It is reckoned that 17% of the Kenyan population is on M-Pesa. As a result they don't need to carry cash any more, as everything from a can of Coke to your funeral can be paid for by phone. It works because the cash is held centrally by the bank, thereby enabling transactions to take place at very fast speeds. The average transaction is $30 (£20) because people trust it to do big ticket items.

One of the bestselling handsets contains seven address books, each with a different ringtone, in recognition of the fact that phones are often shared among multiple users. In Lake Victoria there is a woman who travels from village to village by boat topping up phones. Fraud so far has been mercifully rare, although the system is far from perfect in other ways, as cash is not always available in the right place and the existence of lots of people with the same name in some places makes identity checks difficult beyond the phone and pin number you hold. It's a case of "Le mobile, c'est moi".

Kenya's experience is just one example of the amazing impact that mobile phones are having on economic growth in developing countries. A report commissioned by Vodafone, India: The Impact of Mobile Phones found that Indian states with high mobile penetration grow faster economically than those with lower penetration by as much as 1.2 percentage points a year for every 10% increase in the penetration rate. Even if that were only half true it is an astonishing tribute to the power of mobiles as an engine of growth.

Maybe it is because we are not used to the idea of technology transfer coming from poorer to richer nations that industrialised nations have been so slow to realise not only that Africa is leading the world in mobile banking, but that it has big lessons for us. I am surprised Vodafone, which is behind M-Pesa, hasn't introduced a similar service to the UK. It is also a dream opportunity for the government to turn the Post Office into a serious competitor to the banks. Your local post office would be the trusted place to put your money into the system. After that, practically every transfer can be made by mobile. And if anyone thinks it is too difficult - not something that happens much in Africa, it seems - then the Post Office will help out.

If Gordon Brown wants to turn the PO into a "people's bank" he need look no farther. Given the low esteem in which banks are currently held, there could be a stampede to join. And I'd be among the first.